I had trouble with binocular vision and convergence insufficiency after my concussion. I had a Vision Efficiency Evaluation in which it was discovered. My medical eye exam (retina, visual acuity, etc) was all completely normal, but I understand brain injuries sometimes also cause problems with visual field, etc.
I did ten weeks of vision therapy, and they also had me using very low-power reading lenses for a few weeks. As the vision therapy progressed, I didn't need them any more.
My eye issues were definitely contributing to headaches. After the vision therapy, my headaches were less and I was able to do things like reading and driving without always immediately triggering a headache.
It's definitely worth getting your eyes checked, and I think it's also well worth seeing an optometrist who can do a Visual Efficiency Evaluation. I found mine at
http://www.braininjuries.org
Good luck!